I encourage you to try with Foxit PhantomPDF, you could open the textbook then go to "Organize"->"Insert"->"Blank Page". As an student or teacher, you could enjoy educational discounts to purchase Business Edition. Educational subscription pricing of $9.99 / year is available for students and educational institutions only.
You may refer to this link for more info: https://www.foxitsoftware.com/pdf-editor/

Thank you.

Comment

Open the Tools sheet > Pages board. In the Insert Pages territory of the Pages board, select More Insert Options > Insert Blank Page. At that point pick After from the Location Menu and ensure the page you initially explored to is chosen in the Page territory of the exchange box. Snap OK.

Comment

Open the Tools sheet > Pages board. In the Insert Pages territory of the Pages board, select More Insert Options > Insert Blank Page. At that point pick After from the Location Menu and ensure the page you initially explored to is chosen in the Page territory of the exchange box. Snap OK.

I don't think you are talking about Foxit PhantomPDF program. With Foxit PhantomPDF, you could open the textbook then go to "Organize"->"Insert"->"Blank Page" to insert blank pages.